KR101446872B1 - Method and apparatus for verifying radiation dose - Google Patents

Abstract

The present invention relates to a method and an apparatus for verifying radiation dose, which verifies the radiation dose penetrated through an object during irradiation and controls irradiation. According to an embodiment of the present invention, the method for verifying radiation dose may include the following steps: maintaining a database in which information on reference radiation dose and the range of tolerance are stored; irradiating a specific object; measuring the radiation dose penetrated through the specific object; comparing the measured radiation dose with the reference radiation dose; and controlling the irradiation according to the result of the comparison.

Description

[0001] METHOD AND APPARATUS FOR VERIFYING RADIATION DOSE [0002]

The present invention relates to a radiation dose verification method and apparatus, and more particularly, to a radiation dose verification method and apparatus for verifying a radiation dose transmitted through an object during radiation irradiation to control radiation dose.

Radiation therapy uses radiation, such as X-rays, gamma rays, and proton rays, to delay or stop tissue growth of various cancerous and malignant diseases, and further destroys and helps the treatment for the treatment of disease.

Radiation therapy for cancer treatment is a method to investigate the optimal dose of radiation for cancer tissue and at the same time to investigate the minimal radiation dose to normal tissues around cancer tissues to increase the cancer treatment effect without damaging normal tissues.

Many systems or devices should be used for radiation therapy in hospitals. These systems and devices include Electronic Medical Record (EMR), Order Communication System (OCS), Picture Archiving and Communication System (PACS), Radiation Therapy Planning System (RTP), a radiotherapy apparatus (e.g., a linear accelerator (LINAC)), and the like

Among these, the Radiation Therapy Planning System (RTP) is a system for establishing (creating) the patient's radiotherapy plan by the program. It establishes the radiotherapy plan, that is, the information of the radiotherapy plan, and calculates and reviews the radiation dose.

However, the radiation dose calculation performed by the existing radiation treatment planning system is mainly performed before the treatment, and is not largely deviated from the quality management of the movement of the multi-leaf collimator.

Korean Patent No. 10-1090386 discloses an apparatus and a method for solving the problem that may affect the quality and evaluation of the treatment plan due to the different data on the radiation treatment plan for each radiation treatment apparatus.

However, Korean Patent No. 10-1090386 does not disclose a method for verifying the amount of radiation transmitted through an object during irradiation (e.g., during radiation treatment).

Therefore, it is necessary to study how to control the radiation dose by verifying whether the amount of radiation irradiated during irradiation is appropriate.

It is an object of the present invention to provide a radiation dose verification method and apparatus capable of verifying the amount of radiation transmitted through an object during radiation irradiation and controlling radiation irradiation.

According to an embodiment of the present invention, there is provided a method of measuring a radiation dose, comprising: maintaining a database storing information on a reference dose and a tolerance range; Irradiating a specific object with radiation; Measuring the amount of radiation transmitted by the irradiated radiation through the specific object; Comparing the measured radiation dose to the reference radiation dose; And controlling the irradiation of the radiation according to the result of the comparison.

According to an aspect of the present invention, there is provided an information processing apparatus comprising: a database for storing information on a reference dose and a tolerance range; A radiation irradiation unit for irradiating a specific object with radiation; A radiation dose measuring unit for measuring an amount of radiation transmitted through the specific object by the irradiated radiation; A comparing unit comparing the measured radiation dose with the reference radiation dose; And a control unit for controlling the irradiation of the radiation according to the result of the comparison and for controlling the database, the radiation application unit, the radiation dose measurement unit, and the comparison unit.

The method and apparatus for verifying radiation dose according to an embodiment of the present invention can verify the amount of radiation irradiated to an object during irradiation and control the irradiation of radiation based on the verification result.

The method and apparatus for verifying radiation dose according to an embodiment of the present invention can precisely verify the amount of radiation irradiated to a patient during radiation therapy to prevent an accident caused by radiation therapy.

1 is a block diagram of a radiation dose verification apparatus according to an embodiment of the present invention.
2 shows a radiation dose treating apparatus according to one embodiment of the present invention.
3 is a flow chart illustrating a radiation dose verification method in accordance with an embodiment of the present invention.
FIG. 4 is a view for explaining a process of comparing a radiation dose with a contour line comparison among the radiation dose verification methods according to an embodiment of the present invention.
5 to 6 show the result of analyzing the radiation dose based on the gamma index method for the reference radiation dose image and the photographing image.

Hereinafter, a radiation dose verification method and apparatus according to an embodiment of the present invention will be described with reference to the drawings.

As used herein, the singular forms "a", "an" and "the" include plural referents unless the context clearly dictates otherwise. In this specification, the terms "comprising ", or" comprising ", etc. should not be construed as necessarily including the various elements or steps described in the specification, Or may be further comprised of additional components or steps.

1 is a block diagram of a radiation dose verification apparatus according to an embodiment of the present invention.

As shown, the radiation verification apparatus 100 may include a database 110, a radiation application unit 120, a radiation dose measurement unit 130, a comparison unit 140, and a control unit 150.

The database 110 may store information on the reference radiation dose (for convenience, referred to as reference radiation dose information) and tolerance range information. The reference radiation dose information may include data on the amount of radiation to be irradiated to a particular object before irradiation. For example, the reference dose information may include data (e.g., a radiation dose image) about a planned dose in a radiation therapy planning system (not shown) calculated prior to the radiation therapy. In addition, the tolerance range refers to an error range that can be recognized by normal irradiation even if the measured radiation dose does not match the reference radiation dose.

The radiation irradiation unit 120 can irradiate a specific object with radiation based on the previously stored reference radiation dose information. For example, at the time of radiation treatment, the treatment subject may be irradiated based on the planned radiation dose information.

The radiation dose measuring unit 130 can measure the radiation dose transmitted through a specific object. For example, the radiation dose measuring unit 130 may acquire an image including a radiation dose transmitted through a specific object, including an image photographing apparatus, by photographing a specific object.

The comparing unit 140 may compare the measured amount of radiation with the pre-stored reference amount of radiation. In this case, the comparison unit 140 may determine whether the difference between the measured radiation dose and the stored reference radiation dose is within the tolerance range.

The control unit 150 may perform the radiation control according to the comparison result of the radiation amount of the comparison unit 140. For example, when the difference between the measured radiation dose and the stored reference radiation dose is out of the tolerance range, the control unit 150 may stop the radiation examination.

The control unit 150 may control the database 110, the radiation irradiation unit 120, the radiation dose measurement unit 130, and the comparison unit 140 as a whole.

The radiation dose verification apparatus 100 may be implemented as a radiation therapy apparatus. Hereinafter, the case where the radiation dose verification apparatus 100 is implemented as a radiation therapy apparatus will be described as an example.

FIG. 2 shows a radiation therapy apparatus according to an embodiment of the present invention, and FIG. 3 is a flowchart showing a method of verifying radiation dose during treatment using the radiation therapy apparatus of FIG. Hereinafter, a method of verifying the radiation dose will be described with reference to FIGS. 2 and 3. FIG.

2, the radiation therapy apparatus 200 may include a radiation application unit 210, an image capturing unit 220, a needle 240, a comparison unit 250, and a database 260. The radiation therapy apparatus 200 may perform radiation therapy of the treatment patient 230 based on planned treatment plan data in a treatment planning system (not shown). The treatment planning system is a system for establishing (creating) a patient's radiotherapy plan by a program, and it establishes a radiotherapy plan, that is, compiles information of the radiotherapy plan, and calculates and examines the radiation dose. The treatment plan data may include a reference radiation dose image including treatment plan dose information.

The database 260 may store the treatment plan data including the reference dose amount image (S310). In addition, the database 260 may store information on tolerance ranges. The treatment plan data may include one reference dose amount image that is used uniformly throughout the treatment, and may include a plurality of reference dose amount images that match the comparison period of the dose amount (e.g., Amount image).

The radiation irradiating unit 210 may irradiate the treatment patient 230 lying on the bed 240 based on the planned treatment planning radiation dose information in the treatment planning system (S320). The radiation irradiating unit 210 may include a linear accelerator for irradiating the radiation. A part of the radiation irradiated from the irradiation part 210 may be absorbed by the treatment patient 230 and the other part may be transmitted through the treatment patient 230.

The image capturing unit 220 may acquire an image including the radiation dose information transmitted through the treatment subject 230 (S330). The image capturing unit 220 may include an electronic portal imaging device. For example, an image of a treatment patient 230 taken by an electronic portal imaging device includes radiation dose information transmitted through the treatment patient 230.

The image capturing unit 220 may transmit the information about the captured image to the comparing unit 250. [ The information about the photographed image may be transmitted through wired or wireless communication.

The comparing unit 250 can verify whether the radiation dose being irradiated to the treatment patient 230 is consistent with the planned treatment plan dose using the photographed image and the reference dose amount image stored in the database 260 .

For example, the comparing unit 250 may load an imaging image and a reference radiation dose image. The comparing unit 250 may resize or reposition the two images (shot image and reference dose image) loaded to increase the speed of image comparison or to increase the accuracy of the comparison.

The comparing unit 250 may set a region of interest corresponding to the treatment region in two images that have been resized or resized. The region of interest may already be set prior to treatment.

The comparison unit 250 may calculate the difference between the reference dose measured before treatment and the dose of radiation transmitted to the treating patient through comparison of the interest areas of the two images.

For example, the comparison unit 250 may compare the amount of radiation transmitted to the treated patient with the planned reference dose prior to treatment, by comparing the contour of the area of interest.

FIG. 4 is a view for explaining a process of comparing a radiation dose with a contour line comparison among the radiation dose verification methods according to an embodiment of the present invention.

In Figure 4, the reference image is the reference dose, which represents the planned reference dose before treatment. In addition, the test image may indicate the amount of radiation administered to the patient during treatment, as the captured image. If the two radiation doses are of the same shape, the radiation dose is delivered to the patient according to the treatment plan, otherwise the radiation dose is not delivered properly.

When comparing the two images, the comparison region may not be matched. Thus, a process of matching the comparison region through the rotation (-5 to 5 ') and the movement (dx, dy) may be performed.

The frequency domain correlation is obtained by the respective rotation angles and the movement values, and the frequency domain correlation indicates how much the two images coincide. And the Find max of correlation factor is used as a function in a general program and it is done using it, which means that the two images are best matched when this value is highest. That is, FIG. 4 illustrates a process of finding a comparison region between two images using an outline.

When the process of searching for the comparison region is completed, the comparison unit 250 may compare the two images. An example of such a method is a gamma index method.

Gamma indices are the most widely used method of comparing radiation dose distributions, developed by Daniel A Low at Harvard University Hospital in 1998. The gamma index method combines the distance to agreement with the dose difference and the dose, and compares them with one index. If the gamma index is less than 1 at each point, .

5 to 6 show the result of analyzing the radiation dose based on the gamma index method for the reference radiation dose image and the photographing image. In FIGS. 5 to 6, (a) and (b) illustrate a reference radiation dose image and a photographed image, respectively. The radiation dose was compared using a gamma index. The region (blue portion) having the gamma index value of 1 or less indicates a portion where the radiation amount of the two images coincide well, and the region (red portion) having the gamma index value of 1 or more indicates a portion where the radiation amount of the two images does not coincide well.

FIG. 5 shows that the radiation dose analysis based on the Gamma index (where the blue or greenish portion is a good fit) and the calculated values (calculated values in the treatment planning stage) . As a result of the above results, it can be confirmed that the radiation is well transmitted as originally planned in the treatment planning system.

If the result is analyzed in real time or every predetermined period, the radiation dose verification method can be performed in real time.

For example, the comparative analysis may be performed every 5 seconds or every 10 seconds during patient treatment. In this case, a plurality of reference dose images may be stored in the database 260 so as to match the comparison period.

FIG. 6 is a graph showing that a discordant part (red part) in the gamma index analysis becomes significantly larger when intentionally wrong radiation dose is examined.

Thus, using the gamma index method, the radiation probe 210 (e.g., a treatment beam) can be visually perceived when irradiating a different radiation than originally intended in the treatment planning system.

On the other hand, if the radiation is irradiated to the patient differently than originally intended in the treatment planning system, the difference can be expressed numerically by various means.

If the difference in the radiation dose of the two images acquired through the comparative analysis exceeds the tolerance range, the irradiation for the patient treatment may be stopped (S350, S360). If the difference in the radiation dose of the two images obtained through the comparative analysis is within the tolerance range, the irradiation for the patient treatment may continue

The above-described radiation dose verification method may be implemented in the form of a program command that can be executed through various computer means and recorded in a computer-readable recording medium. At this time, the computer-readable recording medium may include program commands, data files, data structures, and the like, alone or in combination. On the other hand, the program instructions recorded on the recording medium may be those specially designed and configured for the present invention or may be available to those skilled in the art of computer software.

The computer-readable recording medium includes a magnetic recording medium such as a magnetic medium such as a hard disk, a floppy disk and a magnetic tape, an optical medium such as a CD-ROM and a DVD, a magnetic disk such as a floppy disk, A magneto-optical media, and a hardware device specifically configured to store and execute program instructions such as ROM, RAM, flash memory, and the like.

The recording medium may be a transmission medium, such as a light or metal line, a wave guide, or the like, including a carrier wave for transmitting a signal designating a program command, a data structure, and the like.

The program instructions also include machine language code, such as those generated by the compiler, as well as high-level language code that can be executed by a computer using an interpreter or the like. The hardware devices described above may be configured to operate as one or more software modules to perform the operations of the present invention, and vice versa.

The above-described radiation dose verification method and apparatus are not limited to the configuration and method of the above-described embodiments, but the embodiments may be modified such that all or some of the embodiments are selectively And may be configured in combination.

100: Radiation dose verification device
110: Database
120:
130:
140:
150:
200: Radiotherapy device
210:
220:
230: Therapeutic patient
240: Bed
250:
260: Database

Claims (10)

Maintaining a database in which information about the reference radiation dose and information about the tolerance range is stored; the information on the reference radiation dose comprises a planned radiation dose image in the radiation treatment planning system prior to the radiation therapy, Means an error range that can be recognized by normal irradiation even if the measured radiation dose does not match the reference radiation dose;
Irradiating a specific object with radiation based on the information on the reference radiation dose;
Measuring the amount of radiation transmitted by the irradiated radiation during the irradiation of the specific object;
Comparing the measured radiation dose to the reference radiation dose; And
And controlling the irradiation of the radiation according to the comparison result,
Wherein the step of measuring the radiation dose includes the step of acquiring an image including the radiation dose information transmitted to the specific object using the electronic portal imaging apparatus,
Wherein the comparing of the radiation dose comprises: adjusting at least one of a size and a position of the reference radiation dose image and the photographed image; Setting a region of interest in the reference radiation dose image and the photographed image in which at least one of the size and the position is adjusted; Extracting contour lines in the set region of interest; And comparing the amount of radiation transmitted to the specific object with the reference amount of radiation through comparison of the extracted contours. The method according to claim 1,
And stopping the irradiation of the radiation when the difference between the measured radiation dose and the reference radiation dose exceeds the tolerance range. The method according to claim 1,
The radiation dose comparison step may be performed at predetermined intervals,
Wherein the information on the reference radiation dose includes a plurality of reference radiation dose data matched every predetermined period. delete delete A database storing information on the reference dose and information on the tolerance range, the information on the reference dose includes a projected dose amount image in the radiation treatment planning system prior to the radiation treatment, Means an error range that can be recognized as normal irradiation even if it does not match the reference radiation dose;
A radiation irradiating unit for irradiating a specific object with radiation based on the information on the reference radiation dose;
A radiation dose measuring unit for measuring an amount of radiation transmitted through the specific object during the irradiation of the radiation;
A comparing unit comparing the measured radiation dose with the reference radiation dose; And
And a control unit for controlling the irradiation of the radiation according to the comparison result and controlling the database, the radiation application unit, the radiation dose measurement unit, and the comparison unit,
Wherein the radiation dose measuring unit includes an electronic portal imaging apparatus for acquiring an image shot including the radiation dose information transmitted to the specific object,
The radiation dose comparator adjusts at least one of a size and a position of the reference radiation dose image and the photographed image and sets a region of interest in the reference radiation dose image and the photographed image in which at least one of the size and the position is adjusted Extracts a contour line in the set region of interest, and compares the reference radiation dose and the radiation dose transmitted to the specific object through comparison of the extracted contours. 7. The method of claim 6,
And when the difference between the measured amount of radiation and the reference amount of radiation exceeds the tolerance range, the irradiation of radiation is stopped. The method according to claim 6,
Wherein the comparator compares the radiation dose with a predetermined cycle,
Wherein the information on the reference radiation dose includes a plurality of reference radiation dose data matched in the predetermined period. delete delete

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